Chemical synthesis of nanostructured Cu2Se with high thermoelectric performance

作者：Di Li, Xiao Qin, Yong Fei Liu, Ci Song, Ling Wang, Jian Zhang, Hong Xing Xin, Guang Lei Guo, Tian Hua Zou, Guo Long Sun, Bao Jing Ren, Xiao Guang Zhu · 发表于：RSC Advances · 年份：2014 · DOI：10.1039/c3ra47015f · 被引用次数：84 · 研究领域：Advanced Thermoelectric Materials and Devices、Chalcogenide Semiconductor Thin Films、Quantum Dots Synthesis And Properties

Two simplified chemical processes, a co-precipitation and a reduction method, were developed to synthesize pure Cu2Se nanoparticles. The XRD results indicate that the co-precipitation method is a better way to synthesize high-purity Cu2Se in comparison to the reduction method, where a small amount of Cu2O and Cu are found. Scanning electron microscopy reveals that Cu2Se powder synthesized by the reduction method possesses a morphology dominated by irregular hexagonal nanoplates and spherical nanoparticles; however, only nanoplates are observed in powder prepared by the co-precipitation method. The effect of the two synthetic methods on the thermoelectric properties of Cu2Se, in the temperature range of 300–1000 K, was investigated. The results indicate that the co-precipitation method subsequently combined with a hot-press process, is an effective way to improve Cu2Se thermoelectric performance compared to the reduction method together with hot-pressing. The largest figure of merit, ZT, for Cu2Se fabricated by the co-precipitation method is 1.35, which is 40% larger than that of Cu2Se fabricated by the reduction method (ZTmax = 0.97) due to its good power factor at high temperatures.